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Framo Engineering is now part of Schlumberger to create a subsea process and boosting system capable of meeting the demands of the subsea environment and changing flow conditions over the life of a field.

The Gullfaks Field is located in the central part of the East Shetland Basin in the Northern Norwegian North Sea and was discovered in 1979. Statoil developed the Gullfaks Field with three Condeep gravity-based concrete structures and started production in December 1986.

The peak production of over 600,000 bbl/day of oil was reached in 1994, with a recovery factor currently approaching 60%.

After studying multiple solutions to halt the depletion of this Gullfaks Field, Statoil decided to go for a subsea compression unit.

So Framo Engineering has been awarded the contract to design, build and install this subsea compression unit.

With this Gullfaks project, Statoil expects to qualify at full scale this solution to enhance oil recovery(EOR) and thus to expand the life cycle of numerous maturing oil fields in the Norwegian North Sea.

In doing so Statoil consolidates its expertise to move down to the seabed all the Upstream equipment and therefore to increase its Market Leadership in Oil&Gas subsea technologies.

For Framo Engineering the technology is based on multiphase compressors running as counter-rotating Wet Gas Compressor (WGC).

Based on a hydraulic and mechanical design these multiphase compressors are specifically set up for pressure boosting of an unprocessed wellstream and arefully encapsulated, based on a well-proven design.

The Wet Gas Compressor (WGC) concept is ideal for subsea applications with a compact design, without any need for an auxiliary anti-surge control system, inter-cooler or inlet scrubber.

The multiphase compressors is designed in three main parts: upper electric motor, multiphase compressor section, and lower electric motor.

A barrier fluid system is used to provide overpressure protection, lubrication, and continuous cooling of the multiphase compressors‘s critical parts, during all modes of operation.

Theses multiphase compressors includes the following features:

– Slug design to be damped and transported through the compressor without interrupting operation

– High efficiency in the high GLR area, verified up to 85% polytrophic efficiency at 98–100% gas

– High reliability design, with no surge or minimum flow limitations

– High pressure ratio possible due to ”positive density effect”

– High efficiency and low discharge temperature by applying inter-stage mixing and cooling